From Pierced for Our Transgressions: Rediscovering the Glory of Penal Substitution by Steve Jeffery, Michael Ovey, and Andrew Sach:
[A] lack of clarity about what God’s love is leads to a diminished certainty that we have truly encountered it. The vague, nebulous idea of love so prevalent in our society is very fragile. It serves us well when the sun shines down on us, and life is easy, but it offers no defence against the savage onslaught of personal tragedy. It easily gives way to doubt and a feeling of forsakenness at the very moment it is most needed. This is a far cry from the strong, powerful love spoken of in Scripture. Consider Paul’s prayer for the Ephesians: ‘I pray that you, being rooted and established in love, may have power, together with all the saints, to grasp how wide and long and high and deep is the love of Christ, and to know this love that surpasses knowledge — that you may be filled to the measure of all the fulness of God’ (Eph. 5:17-19).
Can any of us honestly say we know Christ’s love this way? Do we experience the tangible intensity of God’s love for which Paul prayer? And if not, where should we look?
The New Testament repeatedly turns to the cross of Christ as the supreme demonstration of the love of God. The apostle John provides the most famous example: ‘This is how we know what love is: Jesus Christ laid down his life for us … God is love … This is love: not that we loved God, but that he love us and sent his Son as an atoning sacrifice for our sins’ (1 John 3:16, 4:8. 10). We can begin to appreciate the contours of God’s love by reflecting on the cost of the cross, the depth of our sinfulness, and the perfection of God’s holiness.
It’s a penal substitutionary understanding of the atonement that gives us the clearest picture of the “intensity and beauty” of the love of God because it does not “diminish our plight as sinners deserving of God’s wrath.”
It also give us assurance that his love will stay with us no matter what. If God gave Christ up on our behalf, “how will he not also with him graciously give us all things?” What could separate us from a love like this?